In PCT Publication WO 98/39983, there is described a sequential flashing circuit for use in an article of footwear and using LED's to generate light pulses which are visible from the rear of the heel of a shoe. The LED's are supplied voltage by a motion activatable switch which changes between an open and closed position by displacement of the shoe. The LED's are illuminated for a period of time in response to a change of the switch from this closed to open position. The motion activated switch is a spring element carrying a switch contact. The spring element is sensitive to movement to cause switch closures.
Canadian Patent 2,124,107 also describes a motion activated light module which is disposed in the heel of a shoe and which operates on the same principle as the above-referenced PCT Publication and wherein a spring is sensitive to impacts or displacement whereby to effect a battery connection. The circuit as herein described is packaged in a module which is incorporated in a cavity formed in the heel of a shoe. Light emitting diodes project from this module and are visible through a transparent portion of the heel of a shoe.